Question: Khan.scratchpad.disable(); For every level Christopher completes in his favorite game, he earns $740$ points. Christopher already has $300$ points in the game and wants to end up with at least $2220$ points before he goes to bed. What is the minimum number of complete levels that Christopher needs to complete to reach his goal?
Solution: To solve this, let's set up an expression to show how many points Christopher will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Christopher wants to have at least $2220$ points before going to bed, we can set up an inequality. Number of points $\geq 2220$ Levels completed $\times$ Points per level $+$ Starting points $\geq 2220$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 740 + 300 \geq 2220$ $ x \cdot 740 \geq 2220 - 300 $ $ x \cdot 740 \geq 1920 $ $x \geq \dfrac{1920}{740} \approx 2.59$ Since Christopher won't get points unless he completes the entire level, we round $2.59$ up to $3$ Christopher must complete at least 3 levels.